1. Field of the Invention
This invention concerns an improved ice making machine and method of controlling it. It more particularly relates to improvements in initiating harvest, terminating harvest, initiating a new freeze cycle, and sensing ice bin full. The invention also incorporates new and improved diagnostic means.
2. The Prior Art
Ice cube makers typically freeze and harvest ice in batches. Ice is formed on an evaporator plate until the desired size and/or thickness is achieved. Once the desired size and/or thickness has been achieved, the machine is put into defrost mode that releases the cubes from the evaporator plate, whereupon they drop into a storage bin.
In the industry, several methods are used to control this cycle of events. Some equipment relies on suction line temperature to signal the end of the freeze cycle. At the end of the freeze cycle, the harvest cycle would begin. The harvest cycle is frequently a defrost cycle on the evaporator plate, often controlled by an adjustable timer. Ice cube bin level control is at times achieved through the use of a thermostat. Because some of the system relies on thermostats and timers, ambient conditions can significantly effect performance of ice cube machines. As might be expected, ambient conditions can differ widely. Accordingly, ice cube machines as delivered to the customer rarely perform satisfactorily without adjustment to the specific ambient conditions of its operating environment. A very large percentage of ice cube making machines require adjustment at least once within the first 60 days of operation.
It is believed that simple changes can be made to currently available ice cube machines to make them operate more satisfactorily even with variations in ambient conditions.